Using complementary approaches of vitamin A deficiency and mice for which response to the vitamin A metabolite RA, was abrogated in T cells, we identified a previously unrecognized role for retinoic acid and its receptor, retinoic acid receptor alpha in the control of dendritic cells function and development. Notably, we found that RA regulates pre-cDC differentiation and that vitamin A deficiency has major consequences on the development of mucosal dendritic cells. Further our work reveals how the immune system adapts to various states of malnutrition by boosting defined aspects of innate responses.